Stool



FIG. 1 is a perspective view of a stool, showing our new design from the front, top and left side;

FIG. 2 is a perspective view thereof, from the rear, top and right side;

FIG. 3 is a rear elevational view thereof; and,

FIG. 4 is a top plan view thereof. 

CLAIM The ornamental design for a stool, as shown and described. 